Abstract: A backlight control system is configured to control a backlight of a display that includes light sources positioned at light source positions for providing illumination to the backside of the display panel. The system includes a drive value generator configured to provide light source drive values for causing the backlight profile to gradually descend around a high luminance portion of the display at a rate that is independent of a position of the high luminance portion with respect to the light source positions. The high luminance portion of the display has a higher luminance than an area around the high luminance portion of the display.

Abstract: A backlight control system for controlling a backlight of a display. The display (100) comprises a transmissive display panel (102) and a backlight (104) for providing an illumination to a backside (108) of the display panel. The backlight comprises light sources (110) positioned at light source positions for providing illumination to the backside of the display panel. The system comprises a drive value generator (106) for providing light source drive values (112) for causing the backlight profile to gradually descend around a high luminance portion of the display at a rate that is independent of a position of the high luminance portion with respect to the light source positions. The high luminance portion of the display has a higher luminance than an area around the high luminance portion of the display. The system allows to prevent a disturbing perception of backlight structure and halo.

Abstract: A block artifacts detection device (100) for detecting block artifacts in a video signal is disclosed. The block artifacts detection device (100) comprises: computing means (102) for computing a gradient signal on basis of the video signal; establishing means (104) for establishing a list of samples corresponding to respective local maximum values of the gradient signal; a histogram determining means (106) for determining a histogram of inter-sample distances, a first one of the inter-sample distances corresponding to a first distance between a first one of the samples and a second one of the samples succeeding the first one of the samples, and a second one of the inter-sample distances corresponding to a second distance between the first one of the samples and a third one of the samples succeeding the second one of the samples; and analyzing means (108) for analyzing the histogram of inter-sample distances and for producing a block artifact indicator on basis of the histogram.

Abstract: A motion sequence pattern detector (200,300) for detecting a periodic pattern of motion sequences within a succession of video fields (100,102) comprises a motion detection unit (202) for detecting presence of motion between pairs of fields of the succession of video fields (100,102) by means of computing differences between pixel values derived from first and second fields of the pairs of fields, succeeded by comparing the differences with a number of predetermined pixel value difference thresholds and for outputting motion detection signals for the pairs of fields on basis of the comparisons; and a pattern recognition unit (204) for detecting the periodic pattern by comparing the number of sequences of the motion detection signals for the pairs of fields with a predetermined sequence. If for one of the number of sequences the periodic pattern is detected then a final output is generated which indicates that the succession of video fields corresponds to film mode.

Abstract: A motion sequence pattern detector (300,301) for detecting presence of film material in a series of consecutive video fields (pp,p,c), is arranged to compute for a first one of the consecutive fields a value of a video motion measure and a value of a film motion measure and to determine the presence of film material on basis of both motion measures. The value of the video motion measure is computed by: establishing a plurality of motion patterns for respective groups of pixels of the first one of the consecutive fields; comparing each of the plurality of motion patterns with a predetermined video motion pattern and conditionally increasing the value of the video motion measure. The value of the film motion measure is computed by comparing each of the plurality of motion patterns with a predetermined film motion pattern and conditionally increasing the value of the film motion measure.